Stub Rails dispatcher so it does not get controller references and simply return the controller#action as Rack::Body.

Methods
C
D
Instance Protected methods
controller_reference(controller_param)

Source: show | on GitHub 

# File actionpack/test/abstract_unit.rb, line 194
def controller_reference(controller_param)
  controller_param
end
dispatch(controller, action, env)

Source: show | on GitHub 

# File actionpack/test/abstract_unit.rb, line 198
def dispatch(controller, action, env)
  [200, {'Content-Type' => 'text/html'}, ["#{controller}##{action}"]]
end